Even though it is not a direct implementation, I hope this could be helpful:

We just launched integration with Integromat platform, which helps to build automated workflows. We also provide several templates for quick start, and one of them allows to copy google calendar events into WA events. So if you share a google calendar for events submission, then the scenario could copy submitted events into your Wild Apricot account.
You can try this integration by this link https://www.integromat.com/en/integration/2275-copy-google-calendar-into-wild-apricot-events